Mashing In An Oven

[Guysmiley54]

Hi guys, just had an interesting thought....

I work in a cafe with a high end Rational combi oven at my disposal http://www.rationalaustralia.com.au/produc...products_id/119 Temperatures can be digitally controlled in 1 degree steps from as low as 30C. Further more, it has a built in temperature probe to control the internal temperature of the food you're cooking.

Surely this would have to be the perfect mashing machine!!! I will have to have a look when I get to work today if I can fit any of my pots inside. It's a big oven but may not fit my 50 litre. I'm thinking that I may get away with two 19 litre Big W pots (which I already have). Failing that, the oven holds very deep trays. I could use 2-3 and surely hold enough liquor... If it works, it may be a great way to try step mashing as the oven heats up and cools down extremely fast.

Has anyone tried this before? Any pitfalls I should consider?

 

[scoundrel]

id be interested in how this goes, i have access to a similar oven at work as well.

 

[vykuza]

The only thing I can think if is that you'll need to stir it regularly, and that may effect the oven's ability to maintain the temperature? Otherwise, I don't see why it wouldn't work.

 

[Brown_hound]

Hi guys, just had an interesting thought....

I work in a cafe with a high end Rational combi oven at my disposal http://www.rationalaustralia.com.au/produc...products_id/119 Temperatures can be digitally controlled in 1 degree steps from as low as 30C. Further more, it has a built in temperature probe to control the internal temperature of the food you're cooking.

Surely this would have to be the perfect mashing machine!!! I will have to have a look when I get to work today if I can fit any of my pots inside. It's a big oven but may not fit my 50 litre. I'm thinking that I may get away with two 19 litre Big W pots (which I already have). Failing that, the oven holds very deep trays. I could use 2-3 and surely hold enough liquor... If it works, it may be a great way to try step mashing as the oven heats up and cools down extremely fast.

Has anyone tried this before? Any pitfalls I should consider?

Sounds like a pretty sweet way to go about it...

My only worry would be temperature pockets in the wort...

EG. If the probe is in the centre of the mash, and the temp drops, how much heat would the oven apply, and will the temp of the mash nearest the pot walls exceed the mash temp?

Sounds awesome though.. I reckon that'd be your only worry, and not too much of one at that...

Keep us posted!

 

[poppa joe]

There is a YOU TUBE video on mashing in an oven....
Watched it a while ago......Dont know where to find it..
Seems to do the job....GO FOR IT....
Cheers
PJ :icon_cheers:

 

[keifer33]

Not exactly what you are after but I did this for a bit when my pot would fit in my oven just it wasn't on when it was in there. I basically turned the oven on to a temperature slightly above my mash temp and left it for a bit to get nice and hot. Turn it off and put in my pot that was at mash temp with the grain in etc as per normal. Would maintain the temperature quite well over about an hour but it seemed to cool down alot.

Id say go for it but and having it on plus the ability to control temperature will make a big difference. Be interested to see how you go.

 

[Guysmiley54]

I think I'll need to do a test run first. I'll grab a pot of water and run it up to 65 and probe it every 5-10 to see what is happening. My hope with the temp pockets is that the losses in a pro oven should be minimal and that the oven would only kick in for short bursts once in a while. Will this actually happen in reality? I don't know :huh:

Will post back once I get a chance to try it.

 

[dr K]

Apart from the practical considerations (wort transfer, transport unless you boil and ferment at work) its a proven method, so long of course that the oven is accurate at mash temps.

The only thing I can think if is that you'll need to stir it regularly, and that may effect the oven's ability to maintain the temperature? Otherwise, I don't see why it wouldn't work

Concerned as to why you would want to regularly stir your mash, thats really a bit of a no-no in small scale brewing, we are looking at creating a filter bed after all. Any reason why ?

K

 

[Guysmiley54]

Apart from the practical considerations (wort transfer, transport unless you boil and ferment at work) its a proven method, so long of course that the oven is accurate at mash temps.



Concerned as to why you would want to regularly stir your mash, thats really a bit of a no-no in small scale brewing, we are looking at creating a filter bed after all. Any reason why ?

K

Sounds promising... im planning on mashing in around an hour before closing time and then staying back to boil. I have been using a cube lately so taking it home to ferment will be easy. I do have a walk in freezer, I'm wondering how long it would take to chill in there?

 

[[email protected]]

Does it have a rotisery as well? If you are really crafty you could set up an automatic mash stirer. Just turn it off 30 mins before lautering to let the grain settle into a bed.

 

[Guysmiley54]

Does it have a rotisery as well? If you are really crafty you could set up an automatic mash stirer. Just turn it off 30 mins before lautering to let the grain settle into a bed.

No rotissery on this one.

Been reading search results and it seems many out there have been using the oven. It seems the idea is to preheat the oven to a temp hotter than desired mash temp, hit strike temp, dough in, pop it in the oven and turn off the oven. I'm planning on setting my oven to strike temps and heating my water in there. Dough in and dail in my mash temp on the oven, insert my temp probe deep into the mash and let the thermostat keep my temp steady.

I'm hoping my oven is accurate enough that I won't need to stir or agitate at all during the process. I wouldn't bother with this idea in a domestic oven but the Rational CombiMaster is a BEAST :kooi:

Will do a "dry" run tomorrow if I have time

 

[black_labb]

you could roast your own malts with that pretty accurately.

I dont see what the oven has that the pot with an old sleeping bag around it doesnt. if you're worried about the heat dropping put the kettle on and add some boiling water to it part way through the mash.

 

[Guysmiley54]

you could roast your own malts with that pretty accurately.

I dont see what the oven has that the pot with an old sleeping bag around it doesnt. if you're worried about the heat dropping put the kettle on and add some boiling water to it part way through the mash.

What this particular oven has is a temperature probe and a thermostat. Set and forget (hopefully h34r: )

 

[Thirsty Boy]

You might have trouble "step" mashing in it unless you have an ability to stir the mash. Which is why you would want to DrK - an oven is just another form of direct heating, and if you want the probe in the mash to reflect any sort of average temperature, it needs to be a stirred mash, just like any other directly heated mash (during stepping). Anyway I dont understand why stirring would or could be an inherrently undesirable thing in small scale brewing. A mash bed sets in minutes. I've witnessed a number of brews where the mash was conducted in a simple pot and transfered to a pail with a false bottom in it as a dedicated lauter tun. Bit of gentleness in the scooped transfer, five minutes to settle, 4 or 5L of vorlauff and crystal clear wort running into the kettle. Any batch sparger knows that stirring is not only OK - its necessary for the technique.

In the oven, for an isothermal mash - you'd just set the oven to the temp you want the mash to be, mash in with an appropriate amount of water at the right temp as you normally would... And the oven holds it spot on for the whole mash. People only turn the oven off because very few home ovens have any sort of ability to be controlled at mash temperatures - your work oven sounds like ithas no such issues.

You could do a "ramp" mash though. Mash in at a certain temp, let it rest there for however long you want, then turn teh temp up to for instance, mashout temps. The whole mash would slowly rise to the set temp - it would not do so uniformly throughout the mash, but in a given pot, in your oven, assuming you dont muck about with it - it would do so predictably and repeatably. So you could just experiment a bit to work out the sort of ramp schedule that gives you the results you want. Bit of a stir towards the end to get it uniform and settle it at mashout temps... Transfer to lauter tun and go.

 

[A3k]

If youre not going to step, id consider putting the temp probe in the air, not in the mash.

Get the mash to the temp you want, then put it in the oven. You can stir the mash and make sure the temp is correct.

When you put it in the oven, the temp of the oven should be at the same temp as the mash, so therell be no heat transfer, so no cold/hot spots.

If the oven was set to 67C with the probe was in the middle of the mash, and your initial temp was actually 66C, thered be a lot of energy required to get the middle of the mash to 67C, at which time the outside would be much hotter than 67.

If you want to step/ramp, accuracy wouldnt be as good, and youd have to use experience as TB mentioned.

 

[vykuza]

Concerned as to why you would want to regularly stir your mash, thats really a bit of a no-no in small scale brewing, we are looking at creating a filter bed after all. Any reason why ?

K

I'd be worried about the inconsistency in temperatures throughout the mash. You're heating it from outside/all around, and mashing grain can't have a terribly amazing thermal transfer properties. The outside of the mash will get hot hot, while the heat slowly transfers through to the middle of the mash.

That's why, I gather, RIMS and HERMS both have the "R" in their names - gotta move the heat around somehow.

 

[jayse]

There are many ways why this would not be ideal, first and this proberly means nothing to many but you will be at work and have work to do, is the plan to put it on at the end of the day then take it home and transfer to lauter tun and carry on or is the plan to do everything at work?

I think just because it might work ok does not justify actually doing it, I can't see how it will provide anything that cannot be done at home with standard equipment. Might sound negative but i think it sounds like a bit of stuffing around for no real gain.

 

[Bribie G]

In my partial mash days I considered trying it, as Americans - especially in the Northern States - seem to be fond of the system and I read about it a lot on forums there. I posted a few times, trying to help newbies there, saying that a good method of doing a small partial was just to float a big Tupperware in a water bath at 68 in an eski, and every time I suggested that, at least two or three posters would fire back "why the heck would you do that if you have an oven available to do it in, kangaroo duude " :unsure:

fortunately my partial stage was only about 2 months and I got into AG.


I reckon it would work for a full mash but you'd need a strong back and a good pair of gloves.

 

[wynnum1]

Couldd you use copper tube to transfer heat into the center of the mash mash

 

[Guysmiley54]

Well I did a test today towards the end of the day.

I 3/4 filled a 19 litre pot with cold water set the oven to 65 and put the probe in the water. I was hoping that the oven probe would work like a thermostat and control the heat to get it to the target reasonably quickly. The oven was above my target temperature and started blowing cold air to cool the oven down. I could monitor the water temp the whole time using the probes readout. It was taking forever so I turned the oven up to 300, it got almost there in about 5 minutes!! I got up to 65 very quickly and turned the oven back to 65. Unfortunately the pot was so hot that the water continued to rise up to the high 70s.

Right... Time for "Plan B" I took the pot out and added cold water to bring it back to 65 and tried to cool the oven down by using the cooling cycle. The oven was then about 80 so I put the pot back and set the oven on 65. As the oven was still trying to drop 15 degrees and was blowing cold air, my water dropped back to 60. Hmm... time to think.... At this stage I found a way to set the target probe temp to 65 but the oven temp to 100. I did this and waited. The water hit 65 again and a continuous alarm went off while the oven continued to heat up. This is not what I had hoped for the temperature probe feature. It would have been great to set oven temp as desired and stick that thing into a juicy big fillet of beef with the alarm to go off at perfect medium rare temp, but that's another story.

Long story short. After using my trusty digital probe from home I can confirm that the oven is calibrated pretty accurately. I can also fit 2 x 19 Litre pots. I reckon if I get my mash and oven to the correct temperature independantly/simultaneously and then start the mash, I will have a better chance of success. I have also realised that it is pretty cool that my esky will keep mash temperatures within 2-3 degrees over an hour with no fiddling or fussing, I used to think that was a bad loss of heat...

I will repeat my experiment toward the end of a shift another day. I would like to be able to brew at work (but ferment at home) I have a wife and two kids and it's hard to spend 4-6 hours at home making a mess without someone getting in the way (often I'm getting in the way of the rest of the household!!) Also, I own the business, so I spend some time after work there anyway.